Optical: systems and elements – Deflection using a moving element – Using a periodically moving element
Patent
1994-11-08
1996-05-07
Pascal, Leslie
Optical: systems and elements
Deflection using a moving element
Using a periodically moving element
359194, H04B 1006
Patent
active
055151973
ABSTRACT:
A coherent optical multichannel receiver includes a frequency down-conversion stage (10) having a laser local oscillator (12) for producing an IF signal which is applied to two frequency detection paths (26,28), the outputs from which are subtracted in a subtractor (30) to provide a data signal. AFC signal producing means (18,34) are also connected to the subtractor (30). In order to avoid a false lock occurring when the receiver is out-of-lock, detection means are provided for detecting an out-of-lock situation. The detection means is coupled either to a bandpass filter (36 or 38) to alter a property of the bandpass filter when the receiver is out-of-lock so that the subtractor (30) provides a positive output which is used to offset the frequency detection characteristic so that it has a single positive zero crossing or to an offset voltage input V.sub.ofs in the AFC loop. The offset is removed automatically when the receiver returns to a lock situation.
REFERENCES:
patent: 4556866 (1985-12-01), Gorecki
Hooijmans Pieter W.
Mols Petrus P. G.
Tomesen Markus T.
Kraus Robert J.
Pascal Leslie
U.S. Philips Corporation
LandOfFree
Coherent optical multichannel receiver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coherent optical multichannel receiver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coherent optical multichannel receiver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1231703